• Journal of the Korea Institute of Building Construction
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• v.14 no.2
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• pp.187-194
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• 2014

With environmental regulations continuously being strengthened internationally the need to control environmental pollution and environmental load is emerging in Korea. The purpose of this study is to seek methods or using waste cementitious powder as an alternative raw material for limestone through the optimization of raw material and to quantitatively analyze the resulting reduction of $CO_2$ emission in order to contribute to solving the issue of waste, which is the biggest issue in relation to construction and global warming. The results of the study, show that waste cementitious powder can be used as an alternative raw material for limestone at OPC level, but it was also found that mixing fine aggregate cementitious powder into waste cementitious powder significantly affected the substitution rate for limestone with waste cementitious powder and the reduction of greenhouse gas. In particular, when fine aggregate cementitious powder was used at a rate of 0~20%, the substitution rate for limestone and the reduction in the rate of greenhouse gas emission was significantly reduced. It is thought that a technique to efficiently separate and discharge the fine aggregate cementitious powder mixed in waste cementitious powder needs to be developed in the future.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.5
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• pp.554-564
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• 2002

A newly designed combustion chamber of diesel engine with a modified piston crown was prepared for the purpose of investigation for reduction of NO emission. It was intended to realize 2-stage combustion that is to keep fuel rich condition during early stage of combustion and fuel lean condition during next stage. The engine was tested on various conditions concerning exhaust gas emissions especially about NO emission and simultaneously fuel consumption rate. It was found that the engine with 2-stage combustion type piston emits significantly low NO at various speed and torque compared with conventional engines, but it raised points at issue in CO and smoke emissions with fuel consumption rate. The increasing of injection pressure on 2 stage combustion type diesel engine affects on CO and smoke emission considerably to reduce but slightly on NO to increase. The effect of 2-stage combustion was better at low speed than at high speed.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1389-1394
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• 2003

$CO_2$ is a well-known green house gas, which is the major source of global warming. Many researchers have studied to reduce $CO_2$ emission in combustion processes. Among the method for reducing $CO_2$ emission, oxygen-enriched combustion has been proposed. But the adiabatic flame temperature is too high. So existing facilities must be changed, or the adiabatic flame temperature in the combustion zone should be reduced. The combustion characteristics, composition in the flame zone, temperature profile and emission gases were studied experimentally for the various oxygen-enriched mtios(OER) by addition of $CO_2$ under coustant $O_2$ flowrate. Results showed that the reaction zone was quenched, broadened, as addition of $CO_2$ was increased. Temperature has a large effect on the NOx emission. The emission of NOx in flue gas decreased due to the decreased temperature of reaction zone. It was also shown that the reaction was delayed by the cooling effect. As the addition of $CO_2$ was increased, the composition of CO in the flame zone increased due to the increase of reaction rate by increasing mixing effect of oxidant/fuel at OER=0, but the composition of CO decreased by quenching effect at OER=50 and 100%.

• Journal of Environmental Impact Assessment
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• v.16 no.4
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• pp.277-283
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• 2007

Since the Kyoto Protocol became into effect, Korea has been expected to be part of the Annex I countries performing the duty of GHG reduction in the phase of post-Kyoto. Therefore, it is necessary to develop emission factors appropriate to Korean circumstances. In order to develop emission factors this study utilized the CleanSYS, which is the real-time monitoring system for industrial smoke stacks to calculate the emission rate of $CO_2$ continuously. In this study, the main focus was on the power generation plants emitting the largest amount of $CO_2$ among the sectors of fossil fuel combustion. Also, an examination on the comparison of $CO_2$ emission was made among 3 generation plants using the different types of fuels such as bituminous coal and LNG; one for coal and others for LNG. The $CO_2$ concentration of the coal fired plant showed Ave. 13.85 %(10,384 ton/day). The LNG fired plants showed 3.16 %(1,031 ton/day) and 3.19 %(1,209 ton/day), respectably. Consequently, by calculating the emission factors using the above results, it was found that the bituminous coal fired power plant had the $CO_2$ emission factor average of 88,726 kg/TJ, and the LNG fired power plants had the $CO_2$ average emission factors of 56,971 kg/TJ and 55,012 kg/TJ respectably which were similar to the IPCC emission factor.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.737-741
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• 2007

This paper analyses the environmental effect of 100kw PV system installed in Tibet using Life Cycle Assessment(LCA). Then, energy payback time(EPT) and life-cycle $CO_2$ emission rate are estimated based on life-cycle of the PV system. As a result of the estimation, 6 year of EPT and 20 g-C/kWh of $CO_2$ emission rate are obtained. In China, average $CO_2$ emission rate of fossil fuel power generation plant is 260 g-C/kWh. This shows that PV system would be very promising for global environmental issues. For advanced LCA, we need to collect detailed and various data about raw material of PV system.

• Journal of the Korean Society of Combustion
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• v.13 no.1
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• pp.1-9
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• 2008

Emission characteristics of NOx and CO with heat loss under high efficiency combustion conditions of $CH_4$/Air prmixed flame were examined numerically using detailed-kinetic chemistry. The one-dimensional combustor length was fixed 5cm, and the equivalence ratio was varied from 0.75 to 0.95. To consider the effects of heat loss on NOx and CO formation, the radiative heat loss rate and combined heat loss rate of conductive and convective heat transfer are included. The following conclusions were drawn. In order to reduce the NOx and CO emission level simultaneously, the temperature of product gases must be reduced under 1,800K as soon as possible but kept over 1,300K during the residence time which is needed to converge CO to $CO_2$.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.149-154
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• 2001

The emission characteristics, flame stability, the composition of the flame zone and temperature profile were studied experimentally. The compositions of oxydant were varied by substituting $N_2$ with $CO_2$ at the constant $O_2$ concentration. Results showed that flame became unstable due to the high heat capacity, low transport rate and strong radiation effect of $CO_2$ in comparison with those of $N_2$. The reaction zone was cooled, broadened, as the conversion ratio of $CO_2$ to $N_2$ was increased. Temperature has a large effect on the NOx emission. The concentration of NOx in flue gas decreased due to the decreased temperature of reaction zone. It was also shown that the reaction was delayed by the cooling effect. As the conversion ratio of $CO_2$ to $N_2$ was increased, the emission of CO and the higher temperature zone increased due to the decrease of reaction rate by the cooling effect.

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.1
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• pp.55-64
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• 1987

Actual driving pattern of each motor vehicle type was measured and analyzed in Seoul area and vehicle emission rate was measured and traffic data were used to estimate vehicular emission factor and motor vehicle-related air pollutant emission. The analysis of contribution ratio of each vehicle type showed that LPG taxi's took 38.1% of total vehicular CO, gasoline passenger cars 37.5%, therefore, these cars are major sources of CO, gasoline passenger cars took 45.4% of total vehicular HC, motorcycles 25.3%, LPG taxi's 16.2%, so motorcycles can be said to play an important role in HC emission. For NOx, buses and trucks were thought to be major sources as buses took 36.8% and truck 26.4%. Diesel vehicles, on the other hand, took most $SO_2$ and particulate matter emission. Total emission from motor vehicles in Seoul was estimated to be 547 t/day of CO, 68t/day of HC, 163t/day of NOx, 18t/day of $SO_2$ and 19t/day of paticulate matter.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.176-183
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• 2007

An experimental study was performed to investigate the effects of mixing quality, inlet pressure, nozzle diameter on CO emission and radiation characteristics in porous ceramic fiber radiant burners. Observations of combustion characteristics occurring inside the burner system which was insulated fiber mat, were investigated by measuring temperature, CO emission and radiation characteristics. Combustion was achieved at the firing rate of $88{\sim}99$ kcal/hr, inlet pressure of $100{\sim}250$mm$H_2O$. CO emissions were found to be strongly dependent on the operating conditions. There was a tendency that CO concentration increased as the firing rate increases. The reason for rise of CO concentration is that it becomes the relatively rich condition. The fiber burner exhibit significant both spectral intensity peaks in the bands at 2.5${\mu}m$ and 4.0${\mu}m$ relatively, There is a small difference in the variable mixing tube. However spectral intensity increased with the firing rate.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.33-42
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• 2010

Recently, the reduction of greenhouse gases(GHG) for climate change is the most important international issue. In order to control efficiency GHG emission rate reduction, it is essential to establish GHG emission inventory preferentially. The emission of ships that are emitting its $CO_2$ in international waters is becoming chief among the issues which country is put under an obligation. In the IMO reports, shipping is estimate to emit 1,046million tonnes of $CO_2$, which corresponds to 3.3% of global emission during 2007. International shipping is estimated to have emitted 870 million tonnes, about 2.7% of global emission of $CO_2$ in 2007. In this study, the general information of GHG emission, based on fuel consumption statistic, Tier 1, and the emission inventory is calculated to break down in to domestic and international emission. The GHG emission from ships in Korea was total 31,646 Gg $CO_2$-eq in 2009, which is included fishing, Korea flag coastal ship, Korea flag ocean going ship and foreign flag ships. And domestic emission and international emission was 5,398Gg $CO_2$-eq, 7,630Gg $CO_2$-eq and foreign flag ship was 18,618Gg $CO_2$-eq respectively.